The present world enters into an era with high-developed information technologies and blooming electronic industry, and thus various different high-tech products are derived from computers, and mobile communication technologies are developed rapidly, and all these are indispensable to our life and shorten the time and space between people. With the popularity and high utility rate of the present electronic products (such as computers) and communication technologies and the incentives promoted by manufacturers, the market competition becomes increasingly severer, and manufacturers spare no effort to find new ways of attracting consumers to use their products. Since consumers have high demands on the electronic products and communication services, it is one of the important indexes to show whether or not the high-tech products and communication technologies of a country lead other countries by the electronic products and communication service provided by that particular country.
Server is a high-performance computer primarily used as a node of a network for saving or processing data on the network, and a server is generally composed of components such as a processor, a hard disk, a memory and a system bus, etc, and these components are designed specifically for network applications, so that a server can have better processing capability, stability, reliability, safety, expandability, and manageability. Particularly in the present advancement of information technologies and increased demand for information flow, many companies or organizations use servers to provide related information and services including downloads and mails. As a result, servers are used extensively, and thus it is an important issue to find a way of providing an environment with more reliable and humanistic information application services as well as a server with better processing capability and reliability.
To prevent the failure of a server due to various different causes and an interrupt of data access or network service, some manufacturers develop a so-called “dual redundant server system”. Referring to FIG. 1, the system includes a console end 1 and a redundant control end 2, wherein the console end 1 transmits or receives data packets between a server system and a network, such that the server system can transmit and receive data packets (related information and network information including downloads and mails) through the network to provide related network information services.
To avoid the failure of the console end 1 and an interrupt of service of the server system, the console end 1 updates data synchronously with the redundant control end 2, when the console end 1 is under a normal operation state. If the console end 1 is disabled, the redundant control end 2 will take over immediately and become a new console end, so that the server system 1 can continue its service.
However, after a first record of cache data A saved in a cache memory 10 of the console end 1 is mirrored into a first record of mirrored cache data A′, the first record of mirrored cache data A′ is saved in another cache memory 20 (as shown in FIG. 1) of the redundant control end 2. After a second record of cache data B saved in the cache memory 10 is mirrored into a second record of mirrored cache data B′, the second record of mirrored cache data B′ is saved in the other cache memory 20 (as shown in FIG. 2). After a third record of cache data C saved in the cache memory 10 is mirrored into a third record of mirrored cache data C′ and the third record of mirrored cache data C′ cannot be saved in the other cache memory 20 (as shown in FIG. 3), the redundant control end 2 will discard the third record of mirrored cache data C′, and thus the contents stored in the cache memory 10 and the other cache memory 20 will be inconsistent.